Operation; Measurement Procedure; Max/Min; Data Hold - Extech Instruments LT300 User Manual

Operation

Light sensor
1. The light sensor is permanently
attached to the meter by the coiled
cable.
2. Remove the protective cap by
unsnapping it to expose the white
domed light sensor. When the sensor's protective cap is removed, the white domed
light sensor lens will begin to capture light. Replace the cap when the meter is not in
use.
Turn Power ON or OFF
Press the button to turn power on or off. If the display does not switch on, check that
the 9V battery is installed and is fresh.
Selecting Lux or Foot candle units of measure
Press the LUX button to select lux units or the Fc button to select foot candle units.

Measurement Procedure

1. Remove the protective cap from the sensor so that the white domed light sensor is
exposed to the light. For overhead lighting, the sensor can be placed on a desk or
table top. A tripod mount and a tilt stand are located on the rear of the meter for
convenience.
2. The display will indicate the light level in Fc or Lux.
3. Press the RANGE button to select the range that provides the maximum resolution. If
the 'OL' appears the light measurement is out of range. Select another range using the
RANGE button.
4. Press the backlight button to illuminate the LCD display if needed.

MAX/MIN

The Max/Min function allows for recording and display of the maximum and minimum light
levels over time.
1. Press the MAX/MIN button. The MAX display icon will appear and meter will now
display and hold only the highest reading. The display will update only when a higher
reading is measured.
2. Press MAX/MIN button. The MIN display icon will appear and meter will now display
and hold only the lowest reading. The display will update only when a lower reading is
measured
3. Press MAX/MIN again. The MAX MIN display icons will appear flashing and meter will
now display the current reading, but will continue to record the highest and lowest
values.
4. Press MAX/MIN again to cycle through MAX and MIN displays.
5. To exit the MAX MIN mode, press and hold the MAX/MIN button until the MAX and
MIN icons completely disappear.

Data Hold

Press the HOLD button to freeze the displayed reading. The " MANU HOLD" hold icon will
appear on the display. Press the HOLD button again to return to normal operation. When
the Data Hold function is enabled the analog bar graph will continue to display level
changes.
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LT300 V2.0 6/06